1. Field of the Invention
The present invention relates to an electronic apparatus that gives a sense of touch of a vibration to a finger when a touch operation of an operating body is performed using the finger, and a vibration control method of controlling the vibration.
2. Description of the Related Art
Hitherto, electronic apparatuses with vibration feedback have been proposed which give a sense of touch of a vibration to a finger when the finger is touched to an operating body to thereby bring the operating body into operation.
Among them, an electronic apparatus has been proposed which gives a stimulus to a finger using vibration acceleration capable of being recognized by a Pacinian corpuscle included in the finger for bringing an operating body into operation, thereby allowing an operator to recognize a stimulus.
The Pacinian corpuscle is a receptor observed in the skin, is present sparsely 2 mm or more under the skin, and is able to sense instantaneous stimuli and vibrations. Meanwhile, the peak value of a vibration frequency capable of being sensed by the Pacinian corpuscle is said to be 250 Hz, and a vibration having a vibration frequency closer to 250 Hz has a greater tendency to be sensed.
WO2013/186841 discloses a technique in which information is input by touching a finger to a touch panel in an electronic apparatus such as a smartphone or a cellular phone. The touch panel has a structure in which a vibration is given using a vibration frequency capable of being recognized by the Pacinian corpuscle, and a stimulus is given to a finger for bringing the touch panel into operation.
In the technique disclosed in WO2013/186841, the vibration frequency for giving an acceleration stimulus to the Pacinian corpuscle is always fixed regardless of an elapse of time. According to such a technique, even when a predetermined time has elapsed after the vibration of the touch panel, the acceleration stimulus transmitted to an operator's finger remains in the vibration frequency having a great influence on the Pacinian corpuscle, and thus a vibration transmitted to the finger stays behind. Therefore, there is a problem in that the operator is not able to obtain a sharp and clear operation feeling.